Established in 2004 in response to a growing need for pharmacokinetic (PK) analysis and modelling, the Clinical Pharmacology Analytical Core (CPAC) helps investigators by providing detailed information on drug interactions, quantification of drugs and metabolites, and protein binding of small molecules. CPAC services include preliminary determination of drug metabolism and metabolite identification for future use. These capabilities have been enhanced since acquiring the API 5500 Q-Trap instrument (described below). Once validated in the shared resource, chargebacks are calculated by the IUSCC administration. The process of rational drug design is built upon a strong foundation of biology, chemistry, in vivo pharmacology, and PK. Relevant PK and metabolism studies should be conducted in small animal models or in vitro systems before first drug administration in humans. This allows for the iterative process of implementing structural changes in the drug molecule to optimize the activity of the drug and its pharmacological and PK properties prior to moving to the more regulated and expensive clinical phase of drug development. PK plays an important role in the determination of drug action. The drug discovery process should provide a delicate balance between the chemistry, pharmacology, and PK of the drug. To coordinate these efforts, CPAC is now interacting closely with In Vivo Therapeutics (IVTC), Chemical Genomics, Center for Computational Biology and Bioinformatics, and other IUSCC shared resources. Over the past few years, CPAC and IVTC have worked together to generate data that help Pls better evaluate molecules developed within the IUSCC that show promise as novel cancer drugs. IVTC performs the live phase study {in vivo) and collects samples for CPAC to perform the kinetics. Both core leaders are directly involved in study design prior to project initiation. PK and metabolism data provide important information to guide drug design and treatment in pre-clinical drug discovery (bench) as well as in clinical drug development and treatment (bedside) with efforts focused on evaluation of toxicity and efficacy of new drug candidates. CPAC's state-of-the-art technology and expertise supports research and development of safe and more efficacious drug treatment for IUSCC investigators